[en] A search for pair-produced leptoquarks has been performed using a sample of e⁺e^- collision events collected by the OPAL detector at LEP at e⁺e^- centre-of-mass energies of about 183 GeV. The data sample corresponds to an integrated luminosity of 55.9 pb^-1. The leptoquarks were assumed to be produced via couplings to the photon and the Z⁰ and then to decay within a single fermion generation. No evidence for contributions from leptoquark pair production processes was observed. Lower limits on scalar and vector leptoquark masses are obtained. The existing limits are improved in the region of large decay branching ratio to quark-neutrino. (orig.)

[en] Searches for pair-production of supersymmetric particles under the assumption that R-parity is violated via a single dominant LL anti E,LQ anti D or anti U anti D anti D coupling are performed using the data collected by the ALEPH collaboration at centre-of-mass energies of 181-184 GeV. The observed candidate events in the data are in agreement with the standard model expectations. Upper limits on the production cross-sections and lower limits on the masses of charginos, sleptons, squarks and sneutrinos are derived. (orig.)